1. Field of the Invention
Example embodiments of the present patent application generally relate to a cleaning unit, a process unit incorporating the cleaning unit, and an image forming apparatus incorporating the cleaning unit.
2. Discussion of the Related Art
Image forming apparatuses typically include a cleaning unit disposed together with a rotatable image carrier that bears an image. The cleaning unit includes, for example, a pair of rubber blades disposed in slidable contact with the rotatable image carrier. A lubricant applicator that applies lubricant to the image carrier is disposed between the pair of rubber blades, such that one of the pair of rubber blades is disposed upstream from the lubricant and the other is disposed downstream from the lubricant in a direction of rotation of the image carrier. The upstream rubber blade removes residual toner remaining on a surface of the image carrier while the downstream rubber blade regulates the amount of lubricant applied to the surface of the image carrier to make the lubricant uniform over the surface of the image carrier.
However, over time the pair of rubber blades of the known cleaning unit is susceptible to compression set, in which the blades become permanently bent. As a result, a small gap can be formed between the leading edge of each rubber blade and the surface of the image carrier with which the blades are supposed, to be in contact. This gap is likely to cause insufficient removal of residual toner and uneven regulation of the amount of lubricant.
Moreover, if compression set occurs, because the above-described rubber blades are disposed on either side of the lubricant applicator, that is, disposed upstream and downstream from the lubricant applicator in the direction of rotation of the image carrier, any residual toner remaining on the surface of the image carrier after passing under the upstream rubber blade may need to be dammed by the downstream rubber blade even as the downstream rubber blade regulates the amount of lubricant, which may damage the downstream rubber blade, allowing toner to mix with the lubricant.